Objects with twice the mass feel twice the attraction ... Lurking in the shadows of gravity was his precious special relativity and the essential concept of space-time, and what made that ...

Another concept of Galilean relativity is the addition of velocities ... we are told that the momentum of an object p is equal to the mass times the velocity, but according to special relativity ...

identified the task of characterizing quasilocal mass — “where one does not need to go ‘all the way to infinity’ in order for the concept to be meaningfully defined” — as the number-one unsolved ...

In Newtonian physics, space and time had their independent identities, and nobody ever got them mixed up. It was with the theory of relativity, put together in the early 20th century, that talking ...